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2 Sheets-Sheet 1. HOLMAN 6L KELLY.

.Tempering Scythes. N0,29,973.j Patented sept. 11, 1860.

.zu JMJ/MAW N, PETERS.

. 2 sheetS-shet 2.v HOLMAN & KELLY.

Tempering Scythes.

No.rv 29,973. A l PatentecSept. 11, 1860.v Y

UNITED STATES PATENT OFFICE.

ANSEL HOLMAN AND OLIVER A. KELLY, OF SLATERVILLE, RHODE ISLAND.

MACHINE FOR HARDENING- SCYTHES.

Specification of Letters Patent No. 29,973, dated September 11, 1860.

To all whom 'it 'may concern.'

Be it known that we, ANsnL HOLMAN and OLIVER A. KELLY, of Slaterville,in the county of Providence and State of Rhode Island, have inventedcertain new and useful Improvements in Machinery for HardeningScythe-Blades and other Articles; and we do hereby declare that thefollowing is a full, clear, and exact description of our said invention,reference being had to the accompanying drawings, in which- Figure lrepresents a plan of an apparatus embodying our improvements, Fig. 2represents an end view of the same, Fig. 3 a cross-section thereof atthe line a of Fig. l, and Fig. 4 is a view of the inner face of one ofthe clamps.

The principal object of our invention is to harden scythe bladesautomatically without any other hand work than the placing of the heatedblade in the machine. The apparatus we have devised for this purposeconsists of a set of clamps for holding the blade and of mechanism forimmersing the same in the hardening liquid, moving the clamps thereinuntil the blade is cooled, and delivering the blade after hardening upona suitable receiving table.

Our invention is divided into several parts the object of the first ofwhich is to insure the free access of the hardening liquid to thesurface of the blade while it is prevented from warping by the clamp.

To this end, the first part of our invention consists in combining a setof clamps of suitable size and form to hold the blade between them, withribs arranged upon the faces of the clamps next the blade in such mannerthat the ribs on one side of the blade extend in directions crosswise tothe ribs on the other side of the blade so that the blade to be hardenedis firmly sustained while the hardening liquid is permitted to have freeaccess to its surface, through the spaces between the ribs.

The object of the second part of our invention is to insure the properform of the hardened blade, and it consists in combining a set of clampscurved in a direction the reverse of that in which the blade warps inhardening, with mechanism for closing the clamps upon the blade andimmersing them in the hardening liquid.

The third part of our invention consists in the combination of clampsfor holding the blade with mechanism that immerses them rapidly in thehardening liquid, and then moves the clamps slowly therein to give timefor the cooling of the blade.

The fourth part of our invention consists in the combination of clampsfor holding the blade during immersion with mechanism that moves theclamps laterally in the hardening liquid, so as to stir up the liquid,equalize its temperature, and change the position of the liquid incontact with the clamps.

The fth part 0f our invention consists in the combination of clamps forholding the blade during immersion with mechanism that reverses andopens the clamps, so that the blade is delivered automatically from theclamps after hardening.

The sixth part of our invention consists in mounting a receiving tablein such manner with reference to the clamps the mechanism for operatingthe same, and the vat of hardening liquid, that the hardened blades arereceived upon the said table after the hardening has been effected.

The seventh part of our invention consists in the combination of a shaftto which an intermittent rotary motion is to be imparted with acontinuously revolving shaft, by means of a ratchet wheel having teethwhich differ in size secured to the former and a reciprocating pawloperated by the latter; so that the shaft to which the ratchet wheel issecured ceases to revolve when it reaches a position indicated by thelocation of alonger tooth on the ratchet wheel, notwithstanding thecontinued reciprocating movement of the pawl.

The eighth part of our invention consists in the combination of the nextpreceding combination with a second pawl having an intermittentreciprocating motion, so that the ratchet wheel can be set in motionwhen desired by bringing the second pawl into action.

All the parts ofour invention are embodied in the apparatus forhardening scythe blades represented in the accompany- Ving drawings.

The clamps A A, which hold the blade, are mounted upon a pair of arms, BB, which project radially from a rotating shaft C. This shaft extendslengthwise over the center of a vat D, that contains the hardeningliquid, and its journals are supported in suitable boxes which aresecured to the ends of the vat. One of the clamps, A, is rigidly securedto the arms B B; the other clamp (A) is perforated to slide upon thearms toward and from the fixed clamp, so as to grip the blade to behardened between the two and to release it after hardening is effected.The movable clamp (A) is connected with a sliding frame consisting of apair of arms, E E, which slide in perforations in the shaft C, and of across bar F by which the arms are connected at the side of the shaftopposite to the clamps. The ends of the cross bar are fitted with a pairof friction wheels, I) b, which by the rotation of the shaft are borneagainst weighted levers Z (l, the pressure of which forces the movableclamp toward the fixed clamp, so as to secure the blade to be hardenedbetween the two. The ends of the cross bar are also fitted with pins, ff, which bearing against cam blocks g secured to the ends of the vat,prevent the weighted levers from closing the clamps until the propertime. The clamps are curved in a direction the reverse of that in wh-ichthe blade warps in hardening and to the saine extent, so that the bladeis bent in the process of clamping before its immersion in the hardeningliquid and is hardened in this bent form. The adjacent faces of theclamps are fitted with feather edged ribs c e, which in this instanceare cast fast to the clamps, and extend obliquely in opposite directionsacross their faces, so that the ribs upon the opposite faces of theblade cross each other.

Then the scythe blade is entered between the clamps its back rests uponthe upper sides of the arms B B. The ribs of the clamp A, which fitsagainst the flat side of the blade, extend far enough across the clampto bear against the whole breadth of the blade; but the ribs of theclamp A, which fits against the side of the blade on which the ridgeprojects that stiens the blade longitudinally, extend only down to thisridge as shown at Fig. 4, so that the lower ends of the feather edgedribs are in a curve t-he same as that of the scythe blade. Hence theblade is held firmly, while at the same time the hardening fluid ispermitted to have free access to its surface through the space betweenthe ribs.

The proper curve of the clamps is obtained experimentally as follows:Astraight sample blade of the kind tobe hardened is heated to the propertemperature and immersed unclamped in the hardening liquid; then thecurve of the clamps is made the reverse of that which this sample bladeassumes in hardening; and, if on trial, the curvature of the clamps isfound to be not exactly correct, it may be adjusted by filing thefeather edged ribs.

The rapid clamping and immersion of the blade into the liquid in thevat, the slow movement of the clamps in the liquid, and

the delivery of the hardened and cooled blade are all effected by therotation of the shaft C by the following means: rIhe end of this shaft Cis fitted with a ratchet wheel G, having one tooth L (Fig. 2) longerthan the remainder. The teeth of this ratchet wheel are acted upon by apawl I which is pivoted to a lever J, that vibrates upon the end of theshaft, and is connected by a rod I-I with a crank pin a, that projectsfrom the face of a cog wheel K. r1`he teeth of this cog wheel engagewith those of a pinion L secured to a shaft M, to which a continuousrevolving motion is imparted by power. A second pawl I is pivoted to asecond vibrating lever J which is connected by a rod H with the crankpin of a second cog wheel K. This second cog wheel (K) is mounted upon astud z' in such manner that its teeth engage with those of the pinion L,and a portion of its teeth are removed so that it ceases to be driven bythe pinion whenever the space Z, made by the removal of the teeth, comesopposite to the pinion teeth, and consequently then ceases to cause thesecond pawl I to reciprocate and act upon the teeth of the ratchet wheelG. The teeth of the second wheel are caused to engage with those of thepinion by slight-ly turning the second wheel, which operation isconveniently effected by means of a foot lever N fitted with a hanginghook I), whose end engages with the teeth of the second Wheel K.

A pair of straps m are secured to the weighted levers d, and extendacross the vat in the tracks of the friction wheels b b. These strapspass over a pair of pulleys n and are secured to a weight O, so that asthe friction wheels are carried around by the revolution of the shaft C,they are borne upon by the weighted straps m m to hold the movable clampin the position in which it has been placed by the action of theweighted levers. A pair of cam blocks R are also secured to the ends ofthe vat to bear upon the friction rollers Z) Z), and prevent the releaseof the blade between the clamps until the latter rise suiiiciently fromthe hardening liquid. A receiving t-able S is hinged to the hinder sideof the vat and is held in its position by a spring t. This springpermits the inner edge of the table to rise when the clamps in risingpress against its under side; but as soon as the clamps pass, the springdepresses the table to its lowest position, so that it is beneath theclamps and intercepts and receives the blade when the clamps open topermit its escape. The opening of the clamps is effected in thisinstance by the weight of the movable clamp and the sliding frame towhich it is secured, which causes the movable clamp to move from thefixed one when the friction rollers Z) Z) reach depressed portions s sof their cam blocks.

In order to facilitate the operation of the machine the weight of theclamps and their appurtenances upon one side of the shaft C iscounterbalanced by a fixed weight T secured to an arm projecting fromthe opposite side of the sha-ft C.

The operation of the apparatus thus described is as follows. The vat D.is filled with the hardening liquid, and the shaft INI is caused torevolve continuously by means of a belt applied to a pulley secured tothis shaft, or in some other convenient manner. By the revolution ofthis shaft the cogwheel K is caused to revolve and impart a continuousreciprocating movement to the pawl I; but as, in the position in whichthe parts are represented in the drawing, the pawl bears upon theinclined face of a tooth /i which is longer than the range of movementof the pawl, the latter merely slides to and fro upon the ratchet wheelwithout imparting any motion to it or to the shaft C to which it issecured. Then the scythe blades, which have been heated to the propertemperature in a suitable furnace, are subjected one at a time to theapparatus. The workman standing` at the front of the vat drops the bladeedgewise and back downward between the clamps, so that its back restsupon the two arms, and immediately applies his foot to the lever N, bywhich he throws the, teeth of the second cogwheel K into geai` withthose of the pinion L. The turning of the cogwheel by the pinion causesthe second pawl to act upon the teeth of the ratchet wheel and put theshaft C in motion. As the shaft turns, the pins f f pass their ends ofthe cam blocks g g, thus permitting the weighted levers CZ d, which arebearing upon the friction wheels b Z), to force the movable clamp towardthe xed clamp and secure the blade between the two. As the shaftcontinues to turn, the clamps with the blade between them are depressedand immersed in the hardening liquid contained in the vat. The turningof the shaft by the action of the second pawl I ceases as soon as thespace in the teeth of its cog wheel K comes around to the teeth of thepinion, and then this second pawl remains out of gear and motionlessuntil it is again thrown into gear by the movement of the foot lever N,but as the movement of the shaft has turned the long tooth of theratchet wheel past the first pawl I, the shorter teeth are now withinthe range of motion of this pawl, and it, acting upon these short teeth,continues to turn the shaft until the long tooth again comes around toits first position. As the shaft turns under the action of the secondpawl, the clamps are carried around in the vat and are raised therefromin a reversed position; as they pass through the vat the movable clamp,although permitted to yield slightly to the spring of the hardened bladewhich tends to Warp straight from its curved form, is prevented fromreleasing it by the action of the cam blocks It R upon the frictionwheels. The continued raising of the clamps causes them to pass by thereceiving table, which yields and flaps upward to permit their passage,and flaps back again when they have passed; and when the receiving tablehas reassumed its position beneath the edges of the reversed clamps, thedepressed parts 8 s of the cam blocks R R permit the friction wheels Z)b and the sliding frame with the movable clamp to move from the fixedclamp, thus releasing the hardened blade and permitting it to drop fromthe clamps upon the receiving table` After the hardened blade hasdropped the clamps continue to revolve until they are returned to theposition whence they started; in arriving at this position the frictionwheels b Z) are again brought into contact with the weighted levers,which tend to close the clamps, and this closing is prevented by theaction of the blocks g g upon the pins f f. rIhe movement of the shaft Cstops when the long tooth of the ratchet wheel comes within the range ofmotion of the pawl I, so that the clamps remain open and at rest untilthe second pawl is again thrown into gear b the foot lever after thesecond heated blade has been introduced between the clamps by theworkman. Hence the location of the long tooth upon the ratchet wheel,or, in other words, the location of a long space between the actingfaces of two adjacent teeth, determines the particular point at whichthe rotating shaft- C stops.

On examining Fig. 2 it will be seen that the connecting rods H I-I ofthe two vibrating levers J J act upon their respective levers atdifferent distances from their centers of motion, the point ofapplication of the connecting rod H to the vibrating lever of the secondpawl I being nearer the center of motion than the corresponding point ofthe vibrating lever of the first pawl I, while the two crank pins a ahave the same throw. From this arrangement it follows that the secondpawl I moves a greater distance with the same revolution of the drivingshaft M, and turns the shaft C more rapidly than the first pawl (I)does; hence it permits the rapid closing of the clamps and effects theirrapid immersion in the hardening liquid, while the first pawl, actingmore slowly and turning the shaft at intervals, works the clamps throughthe hardening fluid, causing the latter to fiow through the spacebetween the ribs, and gives time for the cooling of the blade betweenthem. lThe movement of the shaft C' while the pawls are retrograding isprevented by a friction brake consisting in this instance of a strap a@acting upon a pulley U secured to the end of the shaft, and a brakelever V, shown in dotted lines in Fig. 3,

&

which is held in place so as to strain the strap upon the pulley by anadjustable pin.

The position of the inner side of the receiving table S with referenceto the clamps is regulated by means of a screw bolt c, upon the head ofwhich the lower side of the table bears. The too great vibration of theweighted levers al, CZ which effect the closing of the clamps, isprevented by stops w with which the ends of the levers come in contactwhen the friction wheels b in their forward movement leave the edges ofthe levers.

The hardening liquid which we prefer to use is water, and we prefer tochange the water in the vat by keeping a stream of water flowing into itfrom a pipe and permitting the surplus water to escape through anoverflow pipe. The speed of the apparatus is such that the clamps whenstarted make a revolution in about 24 seconds. Their lateral movement inthe vat has the effect of stirring up the liquid therein, and equalizingits temperature which is advantageous; and the arrangement of the clampribs obliquely in opposite directions or crosswise to each other reducesthe portions of the blade pressed upon simultaneously by the oppositeribs to the smallest dimensions, and permits the hardening` liquid tohave free access to one side at least of every part of the blade exceptthose small portions where the ribs cross each other.

As the apparatus we have described is a machine which hardens anddelivers the blades automatically without requiring the attention of theworkman after he places the blade between the clamps, and starts themachine, and as the time required for this purpose is exceedingly brief,the workman is left free to devote his time and attention to the heatingof the blades preliminary to hardening.

Although the apparatus thus described is specially adapted to thehardening of scythe blades, we are aware that parts of our invention maybe applied with advantage to the hardening of other articles, theconstruction of the apparatus being properly adapted to thepeculiarities of such articles as circumstances render expedient. le arealso aware that parts of the apparatus we have described may bemodified, but the arrangement and construction of the apparatus which wehave described and represented are the best with which we areacquainted.

That we claim as our invention, and desire to secure by Letters Patent,is-

l. The combination of clamps of suitable size and form to hold the bladeto be tempered with ribs arranged upon the faces of the clamps next theblade to be hardened in directions crosswise to each other,substantially as set forth.

2. The combination of a set of clamps curved in a direction the reverseof that in which the blade warps in hardening, with mechanism forclosing the clamps upon the blade and immersing them in the hardeningliquid, substantially as set forth.

3. The combination of clamps for holding the blade, with mechanism thatimmerses them rapidly in the hardening liquid and then moves them slowlytherein, substantially as set forth.

Ll. The combination of clamps for holding the blade during immersion,with mechanism that moves the clamps laterally in the hardening liquid,substantially as set forth.

5. The combination of clamps for holding the blade during immersion,with mechanism that reverses and opens the clamps, so that the blade isdelivered automatically from the clamps, substantially as set forth.

6. Mounting a receiving table in such manner with reference to theclamps, the mechanism for operating the same, and the vat of hardeningliquid, that the hardened blade is received upon the said table afterhardening is eifected.

7. The combination of a shaft to which an intermittent rotary motion isto be imparted, with a continuously revolving shaft, by means of ratchetwheel having teeth of diiferent size and a reciprocating pawlsubstantially as set forth.

8. The combination of the next preceding combination with a second pawlsubstantially as set forth.

In testimony whereof we have hereunto subscribed our names.

ANSEL HOLMAN. OLIVER A. KELLY. lVtnesses NELooME SMITH, Jos. K. F.MANSFIELD.

